U.S. Pat. No. 3,723,133 to Berry et al, issued Mar. 27, 1973, discloses a dehydrated, deacidified citrus juice product, as well as a method for preparing this product. The method disclosed by this patent involves initial separation of the serum portion of the juice by centrifugation. The serum portion is pasteurized and dry, finely divided calcium or other metal hydroxide is then added to neutralize it. Precipitated calcium citrate is then removed by centrifugation from this neutralized serum, followed by recombination with the juice material residue left after the first centrifugation. This recombined product is concentrated, mixed with a foaming agent and then dried to obtain the dehydrated, deacidified citrus juice product. Besides citrus juices, the Berry et al method can be applied to "any other sugar-containing juice which varies from time to time in acid content." See Col. 3, lines 42-44.
U.S. Pat. No. 2,567,038 to Stevens et al, issued Sep. 4, 1951, discloses a method for preparing dried fruit juice concentrates. In this method, the juice acidity is buffered or partially neutralized by raising its pH, followed by pasteurization. (One of the methods for neutralizing and buffering juice acidity is by addition of an alkaline material such as calcium hydroxide or sodium hydroxide.) This pasteurized juice is then concentrated under suitable vacuum conditions, followed by addition of granular sugar in quantities sufficient to produce a moist, granular mixture. This sugar-juice mixture is dried to provide the dried fruit juice concentrate.
U.S. Pat. No. 2,928,744 to Ponting, issue Mar. 15, 1960, discloses a method for preventing decolorization of apple juice. In this method, the apple fruit is comminuted in the presence of essentially pure malic acid. Excess malic acid can be removed by addition to the juice of sufficient calcium carbonate or calcium hydroxide to restore the pH to its natural level. The excess malic acid precipitates out as calcium malate which can then be removed by filtration. See also U.S. Pat. No. 1,141,458 to Gore, issued Jun. 1, 1915, which discloses a process where calcium hydroxide suspended in water (milk of lime) is added to cider (or other fruit juice) to neutralize the free acids present, passed through a filter press to remove suspended substances, concentrated to provide a syrup containing calcium malate crystals, and then passed through a filter press to separate the syrup from the crystals.
U.S. Pat. No. 4,477,481 to Eisenhardt, Jr. et al, issued Oct. 16, 1984, discloses a method for freeze drying citrus pulp. In this method, wet citrus pulp is processed so that the pH is increased to at least about 4.0, followed by freezing and freeze-drying to a moisture content less than 10% by weight. The pH of the pulp can be increased by the use of potassium or calcium hydroxide.